/*
 * Copyright (c) 2007 innoSysTec (R) GmbH, Germany. All rights reserved.
 * Original author: Edmund Wagner
 * Creation date: 18.06.2007
 *
 * Source: $HeadURL$
 * Last changed: $LastChangedDate$
 * 
 * the unrar licence applies to all junrar source and binary distributions 
 * you are not allowed to use this source to re-create the RAR compression algorithm
 * 
 * Here some html entities which can be used for escaping javadoc tags:
 * "&":  "&#038;" or "&amp;"
 * "<":  "&#060;" or "&lt;"
 * ">":  "&#062;" or "&gt;"
 * "@":  "&#064;" 
 */
package com.github.junrar.io;

/**
 * Read / write numbers to a byte[] regarding the endianness of the array
 * 
 * @author $LastChangedBy$
 * @version $LastChangedRevision$
 */
public class Raw
 {
  /**
   * Read a short value from the byte array at the given position (Big Endian)
   * 
   * @param array
   *         the array to read from
   * @param pos
   *         the position
   * @return the value
   */
  public static final short readShortBigEndian(byte[] array, int pos)
   {
    short temp = 0;
    temp |= array[pos] & 0xff;
    temp <<= 8;
    temp |= array[pos + 1] & 0xff;
    return temp;
   }

  /**
   * Read a int value from the byte array at the given position (Big Endian)
   * 
   * @param array
   *         the array to read from
   * @param pos
   *         the offset
   * @return the value
   */
  public static final int readIntBigEndian(byte[] array, int pos)
   {
    int temp = 0;
    temp |= array[pos] & 0xff;
    temp <<= 8;
    temp |= array[pos + 1] & 0xff;
    temp <<= 8;
    temp |= array[pos + 2] & 0xff;
    temp <<= 8;
    temp |= array[pos + 3] & 0xff;
    return temp;
   }

  /**
   * Read a long value from the byte array at the given position (Big Endian)
   * 
   * @param array
   *         the array to read from
   * @param pos
   *         the offset
   * @return the value
   */
  public static final long readLongBigEndian(byte[] array, int pos)
   {
    int temp = 0;
    temp |= array[pos] & 0xff;
    temp <<= 8;
    temp |= array[pos + 1] & 0xff;
    temp <<= 8;
    temp |= array[pos + 2] & 0xff;
    temp <<= 8;
    temp |= array[pos + 3] & 0xff;
    temp <<= 8;
    temp |= array[pos + 4] & 0xff;
    temp <<= 8;
    temp |= array[pos + 5] & 0xff;
    temp <<= 8;
    temp |= array[pos + 6] & 0xff;
    temp <<= 8;
    temp |= array[pos + 7] & 0xff;
    return temp;
   }

  /**
   * Read a short value from the byte array at the given position (little
   * Endian)
   * 
   * @param array
   *         the array to read from
   * @param pos
   *         the offset
   * @return the value
   */
  public static final short readShortLittleEndian(byte[] array, int pos)
   {
    short result = 0;
    result += array[pos + 1] & 0xff;
    result <<= 8;
    result += array[pos] & 0xff;
    return result;
   }

  /**
   * Read an int value from the byte array at the given position (little Endian)
   * 
   * @param array
   *         the array to read from
   * @param pos
   *         the offset
   * @return the value
   */
  public static final int readIntLittleEndian(byte[] array, int pos)
   {
    return ((array[pos + 3] & 0xff) << 24) | ((array[pos + 2] & 0xff) << 16) | ((array[pos + 1] & 0xff) << 8)
           | ((array[pos] & 0xff));
   }

  /**
   * Read an long value(unsigned int) from the byte array at the given position
   * (little Endian)
   * 
   * @param array
   * @param pos
   * @return
   */
  public static final long readIntLittleEndianAsLong(byte[] array, int pos)
   {
    return (((long) array[pos + 3] & 0xff) << 24) | (((long) array[pos + 2] & 0xff) << 16)
           | (((long) array[pos + 1] & 0xff) << 8) | (((long) array[pos] & 0xff));
   }

  /**
   * Read a long value from the byte array at the given position (little Endian)
   * 
   * @param array
   *         the array to read from
   * @param pos
   *         the offset
   * @return the value
   */
  public static final long readLongLittleEndian(byte[] array, int pos)
   {
    int temp = 0;
    temp |= array[pos + 7] & 0xff;
    temp <<= 8;
    temp |= array[pos + 6] & 0xff;
    temp <<= 8;
    temp |= array[pos + 5] & 0xff;
    temp <<= 8;
    temp |= array[pos + 4] & 0xff;
    temp <<= 8;
    temp |= array[pos + 3] & 0xff;
    temp <<= 8;
    temp |= array[pos + 2] & 0xff;
    temp <<= 8;
    temp |= array[pos + 1] & 0xff;
    temp <<= 8;
    temp |= array[pos];
    return temp;
   }

  /**
   * Write a short value into the byte array at the given position (Big endian)
   * 
   * @param array
   *         the array
   * @param pos
   *         the offset
   * @param value
   *         the value to write
   */
  public static final void writeShortBigEndian(byte[] array, int pos, short value)
   {
    array[pos] = (byte) (value >>> 8);
    array[pos + 1] = (byte) (value & 0xFF);

   }

  /**
   * Write an int value into the byte array at the given position (Big endian)
   * 
   * @param array
   *         the array
   * @param pos
   *         the offset
   * @param value
   *         the value to write
   */
  public static final void writeIntBigEndian(byte[] array, int pos, int value)
   {
    array[pos] = (byte) ((value >>> 24) & 0xff);
    array[pos + 1] = (byte) ((value >>> 16) & 0xff);
    array[pos + 2] = (byte) ((value >>> 8) & 0xff);
    array[pos + 3] = (byte) ((value) & 0xff);

   }

  /**
   * Write a long value into the byte array at the given position (Big endian)
   * 
   * @param array
   *         the array
   * @param pos
   *         the offset
   * @param value
   *         the value to write
   */
  public static final void writeLongBigEndian(byte[] array, int pos, long value)
   {
    array[pos] = (byte) (value >>> 56);
    array[pos + 1] = (byte) (value >>> 48);
    array[pos + 2] = (byte) (value >>> 40);
    array[pos + 3] = (byte) (value >>> 32);
    array[pos + 4] = (byte) (value >>> 24);
    array[pos + 5] = (byte) (value >>> 16);
    array[pos + 6] = (byte) (value >>> 8);
    array[pos + 7] = (byte) (value & 0xFF);

   }

  /**
   * Write a short value into the byte array at the given position (little
   * endian)
   * 
   * @param array
   *         the array
   * @param pos
   *         the offset
   * @param value
   *         the value to write
   */
  public static final void writeShortLittleEndian(byte[] array, int pos, short value)
   {
    array[pos + 1] = (byte) (value >>> 8);
    array[pos] = (byte) (value & 0xFF);

   }

  /**
   * Increment a short value at the specified position by the specified amount
   * (little endian).
   */
  public static final void incShortLittleEndian(byte[] array, int pos, int dv)
   {
    int c = ((array[pos] & 0xff) + (dv & 0xff)) >>> 8;
    array[pos] += dv & 0xff;
    if ((c > 0) || ((dv & 0xff00) != 0))
     {
      array[pos + 1] += ((dv >>> 8) & 0xff) + c;
     }
   }

  /**
   * Write an int value into the byte array at the given position (little
   * endian)
   * 
   * @param array
   *         the array
   * @param pos
   *         the offset
   * @param value
   *         the value to write
   */
  public static final void writeIntLittleEndian(byte[] array, int pos, int value)
   {
    array[pos + 3] = (byte) (value >>> 24);
    array[pos + 2] = (byte) (value >>> 16);
    array[pos + 1] = (byte) (value >>> 8);
    array[pos] = (byte) (value & 0xFF);

   }

  /**
   * Write a long value into the byte array at the given position (little
   * endian)
   * 
   * @param array
   *         the array
   * @param pos
   *         the offset
   * @param value
   *         the value to write
   */
  public static final void writeLongLittleEndian(byte[] array, int pos, long value)
   {
    array[pos + 7] = (byte) (value >>> 56);
    array[pos + 6] = (byte) (value >>> 48);
    array[pos + 5] = (byte) (value >>> 40);
    array[pos + 4] = (byte) (value >>> 32);
    array[pos + 3] = (byte) (value >>> 24);
    array[pos + 2] = (byte) (value >>> 16);
    array[pos + 1] = (byte) (value >>> 8);
    array[pos] = (byte) (value & 0xFF);

   }
 }
